We were discussing the concept of laminar and turbulent flowReynolds experimentfrictional loss in pipes, derivation of expression for loss of head due to friction in pipesco-efficient of friction in terms of shear stress, basics of shear stress in turbulent flow and also the minor head losses in pipe flow, in the subject of fluid mechanics, in our recent posts.

Now we will go ahead to see the concept of hydraulic gradient and total energy line, in the subject of fluid mechanics, with the help of this post.

Concepts of hydraulic gradient line and total energy line will be quite useful when we analyze the problems of fluid flow through pipes. Now we will understand here the concept of hydraulic gradient line and total energy line.

Hydraulic gradient line and total energy line are the graphical representation for the longitudinal variation in piezometric head and total head.

Hydraulic gradient line is basically defined as the line which will give the sum of pressure head and datum head or potential head of a fluid flowing through a pipe with respect to some reference line.

H.G.L = P/ρg + Z

Where,

### Total Energy Line

Total energy line is basically defined as the line which will give the sum of pressure head, potential head and kinetic head of a fluid flowing through a pipe with respect to some reference line.

H.G.L = P/ρg + Z + V2/2g
Where,
T.E.L = Total energy line

### Relation between hydraulic gradient line and total energy line

H.G.L = E.G.L - V2/2g

Let us see the following figure, there is one reservoir filled with water and also connected with one pipe of uniform cross-sectional diameter.

Hydraulic gradient and energy lines are displayed in figure.

At Velocity V = 0, Kinetic head will be zero and therefore hydraulic gradient line and energy gradient line will be same.

At Velocity V = 0, EGL = HGL

Further we will go ahead to find out the basic concept of flow through syphon in the subject of fluid mechanics, with the help of our next post.

You can find out some very important posts based on engineering practices such as Comparison between AC welding and DC welding, Difference Between Arc welding and Gas welding etc.

Some very important topic based on fluid mechanics/machinery could found here with following pages as mentioned here.

Do you have any suggestions? Please write in comment box.

### Reference:

Fluid mechanics, By R. K. Bansal

### We have started something new and exciting .....

Bright Idea Space

We have started another website i.e. https://brightideaspace.com/ that basically provides the new ideas, Creative prompts and challenges, Self-improvement articles, Interviews with successful creatives, Resources and tools, innovative ideas and discuss about the various thought process that will continuously improve our thought process day by day.

Let us see here few posts of https://brightideaspace.com/